At present, in the field of stage lighting, the most widely used functional lamps mainly include three types: spot lights, beam lights, and wash lights, respectively. The stage designers and users tend to the targeted choice of different functional lights according to their requirements. However, due to the single usage, different types of lights are required to be changed and used in a complicated stage scene, which is extremely complicated to operate. In order to solve this problem, a stage lighting realizing various beam effects has also been proposed in the prior art.
Chinese patent CN201320192500.0 has disclosed a stage lighting system including various beam effects simultaneously, which comprises a light source, a reflective bowl, a first optical assembly, and a second optical assembly. Said first optical assembly is located between the reflective bowl and the second optical assembly in a primary optical axis direction. The switchover of the various beam effects is realized through the movement of the first optical assembly. After emitted by the light source, the light passes through the reflective bowl, the second optical assembly, and then a light pillar with a middle beam that is so gathered is formed. Since the middle beam is condensed, the whole light pillar seems to have an obvious beam feeling, and when the beam shines on an imaging plane, there is obvious layering feeling between the spot centre and the spot edge. The above description is the lighting effect of the beam light. After the first optical assembly is added, the beam reflected from the reflective bowl is diverged by the first optical assembly, and then passes through the second optical assembly. The original gathered beam becomes diverged, and when the beam shines on an imaging plane, the effect of the whole imaging spot is relatively uniform. This is the lighting effect of the spot light.
In this structure, the effect of the uniform light or beam is realized through increasing or decreasing the first optical assembly, that is, through increasing or decreasing lens or light guide. However, uniform light and beam are two very different lighting effects. The former one is to diverge light, and the latter one is to condense light. With regard to the structure of the above-mentioned patent, the first optical assembly is located between the light source and the second optical assembly. If it needs to be added directly, it is necessary to reserve sufficient space, which brings certain disadvantages to the choice of the light source. If the space between the light source and the second optical assembly is relatively small, the practicability will be relatively poor. In addition, when switching from the beam effect to the spot effect, and the first optical assembly moves into the position of the primary optical axis, the optimal parameter of the optical position of the first optical assembly, such as light guide, or the light guide and lens assembly has not been considered, leading to relatively big light loss and poor lighting effect of the spot effect light that is eventually realized.